Problem: Rewrite ${((4^{5})(5^{7}))^{-10}}$ in the form ${4^n \times 5^m}$.
Answer: ${ ((4^{5})(5^{7}))^{-10} = (4^{(5)(-10)})(5^{(7)(-10)})} $ ${\hphantom{ ((4^{5})(5^{7}))^{-10}} = 4^{-50} \times 5^{-70}} $